The device that reads from and writes to a floppy disk or hard disk is called a disk drive.

Here's a breakdown:

* Floppy disk drives were used for older computers to store and access data on floppy disks. They are now largely obsolete.

* Hard disk drives (HDDs) are still common in desktop computers and some laptops. They store data on magnetic platters that spin inside the drive.

* Solid-state drives (SSDs) are becoming increasingly popular as replacements for HDDs. They use flash memory to store data and offer much faster performance.

All of these devices use a read/write head to access the data on the disk. The head moves across the surface of the disk, reading or writing data as it goes.